Damage localization in composite panel using contact and non-contact elastic wave generation

In this paper results of the damage assessment of composite panel using the guided wave propagation method are presented. Two approaches of elastic wave generation are investigated: (i) contact, piezoceramic transducer (PZT)-based and (ii) non-contact, air-coupled transducer (ACT)-based. Elastic wave sensing is based on scanning laser Doppler vibrometry (SLDV). Both methods of elastic wave generation are compared based on an analysis of elastic wave propagation and damage localization results. For this purpose wave irregularity mapping (WIM) algorithm was utilized. In this research square panels made of fibre reinforced polymer are investigated. Authors investigate artificial damage in the form of Teflon inserts. In this research low-cost and low-frequency (40 kHz) ACT is utilised. The use of the ACT-based wave generation together with the SLDV-based wave sensing give the possibility of realization of the full non-contact damage localization approach. Moreover, authors analysed the acoustic wave generation by the ACT and its propagation in the air using acousto-optic effect together with SLDV measurements.